A touch panel is installed on a display surface of an image display device such as a cathode ray tube (CRT), a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electro-luminescence device (ELD), so that a user inputs predetermined information into a computer by pressing the touch panel while viewing the image display device.
FIGS. 1 and 2 are views showing main components of a capacitive type touch panel. FIG. 1 is a plan view showing a multi-bonding structure, and FIG. 2 is a sectional view taken along a line X of FIG. 1. Referring to FIGS. 1 and 2, the touch panel generally includes a transparent window 10, an upper OCA 50 provided under the transparent window 10, an upper electrode layer (ITO) 40 provided under the upper OCA 50, a lower OCA 30, and a lower electrode layer 20. In addition, a liquid crystal panel 60 adheres to the bottom surface of the above structure. A touch screen panel TSP formed by bonding various layers to each other has a bonding area C which is formed by cutting the upper OCA 50, the upper electrode layer (ITO) 40, and the lower OCA 30 for the purpose of bonding to an FPCB module and exposes a connection pad P.
The above touch panel includes a printed pattern realized to represent various colors depending on the design of a terminal or hide internal wirings. Although the printed pattern is directly printed on the bottom surface of the transparent window 10, the thickness of the printed pattern degrades the adhesive strength with the upper OCA 50 provided under the transparent window 10, thereby causing the failure of the touch panel.